CVE-2026-44241: CWE-400: Uncontrolled Resource Consumption in micronaut-projects micronaut-core
Micronaut Framework is a JVM-based full stack Java framework designed for building modular, easily testable JVM applications. From 4.3.0 to before 4.10.22, TimeConverterRegistrar caches DateTimeFormatter instances in an unbounded ConcurrentHashMap<String, DateTimeFormatter> whose key is derived from the @Format annotation pattern concatenated with the locale from the HTTP Accept-Language header. Because Locale.forLanguageTag() accepts arbitrary BCP 47 private-use extensions (en-x-a001, en-x-a002, …), an unauthenticated attacker can generate an unlimited number of unique cache keys by sending requests with novel locale tags, growing the cache until heap memory is exhausted and the JVM crashes. This vulnerability is fixed in 4.10.22.
AI Analysis
Technical Summary
The Micronaut Framework's TimeConverterRegistrar caches DateTimeFormatter objects in an unbounded ConcurrentHashMap keyed by a combination of @Format annotation patterns and locale strings derived from the HTTP Accept-Language header. Since Locale.forLanguageTag() accepts arbitrary BCP 47 private-use extensions, an attacker can supply numerous unique locale tags, causing the cache to grow without limit. This uncontrolled resource consumption can exhaust heap memory and crash the JVM. The vulnerability affects versions from 4.3.0 to before 4.10.22 and is resolved in 4.10.22.
Potential Impact
An unauthenticated attacker can cause a denial of service by exhausting heap memory through cache bloat, crashing the JVM hosting the Micronaut application. There is no impact on confidentiality or integrity, but availability is severely affected.
Mitigation Recommendations
Upgrade Micronaut Framework to version 4.10.22 or later where this vulnerability is fixed. No other official remediation or temporary fix is documented. Patch status is not explicitly stated in the vendor advisory but the description confirms the fix in 4.10.22.
CVE-2026-44241: CWE-400: Uncontrolled Resource Consumption in micronaut-projects micronaut-core
Description
Micronaut Framework is a JVM-based full stack Java framework designed for building modular, easily testable JVM applications. From 4.3.0 to before 4.10.22, TimeConverterRegistrar caches DateTimeFormatter instances in an unbounded ConcurrentHashMap<String, DateTimeFormatter> whose key is derived from the @Format annotation pattern concatenated with the locale from the HTTP Accept-Language header. Because Locale.forLanguageTag() accepts arbitrary BCP 47 private-use extensions (en-x-a001, en-x-a002, …), an unauthenticated attacker can generate an unlimited number of unique cache keys by sending requests with novel locale tags, growing the cache until heap memory is exhausted and the JVM crashes. This vulnerability is fixed in 4.10.22.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Micronaut Framework's TimeConverterRegistrar caches DateTimeFormatter objects in an unbounded ConcurrentHashMap keyed by a combination of @Format annotation patterns and locale strings derived from the HTTP Accept-Language header. Since Locale.forLanguageTag() accepts arbitrary BCP 47 private-use extensions, an attacker can supply numerous unique locale tags, causing the cache to grow without limit. This uncontrolled resource consumption can exhaust heap memory and crash the JVM. The vulnerability affects versions from 4.3.0 to before 4.10.22 and is resolved in 4.10.22.
Potential Impact
An unauthenticated attacker can cause a denial of service by exhausting heap memory through cache bloat, crashing the JVM hosting the Micronaut application. There is no impact on confidentiality or integrity, but availability is severely affected.
Mitigation Recommendations
Upgrade Micronaut Framework to version 4.10.22 or later where this vulnerability is fixed. No other official remediation or temporary fix is documented. Patch status is not explicitly stated in the vendor advisory but the description confirms the fix in 4.10.22.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-05T15:42:40.520Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a03a0decbff5d86101d5c82
Added to database: 5/12/2026, 9:51:26 PM
Last enriched: 5/12/2026, 10:07:10 PM
Last updated: 5/13/2026, 4:58:38 AM
Views: 6
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